title: Development of a CD28 receptor binding-based screen and identification of a biologically active inhibitor.
abstract: CD28 is a T-cell costimulatory receptor which plays a pivotal role in antigen-induced T-cell response. We have developed a cell-free and scintillation-proximity assay-based screen to search for molecules that inhibit ligand binding to CD28. The assay was shown to be versatile and adaptable to automation for high-throughput screening. Using this assay, we identified an inhibitor of CD28, NP2214. The inhibitor was shown to be active in vitro by suppressing IL-2 synthesis and proliferation of peripheral blood mononuclear cells in response to CD28 costimulation. We also demonstrated the additive effects of NP2214 and cyclosporine A which act mechanistically distinctly in inhibiting costimulation-induced IL-2 synthesis.
authors.affiliation: Schering-Plough Research Institute, Kenilworth, New Jersey 07033, USA.
authors.forename: C H
authors.initials: CH
authors.lastname: Jenh
authors.forename: M
authors.initials: M
authors.lastname: Zhang
authors.forename: M
authors.initials: M
authors.lastname: Wiekowski
authors.forename: J C
authors.initials: JC
authors.lastname: Tan
authors.forename: X D
authors.initials: XD
authors.lastname: Fan
authors.forename: V
authors.initials: V
authors.lastname: Hegde
authors.forename: M
authors.initials: M
authors.lastname: Patel
authors.forename: R
authors.initials: R
authors.lastname: Bryant
authors.forename: S K
authors.initials: SK
authors.lastname: Narula
authors.forename: P J
authors.initials: PJ
authors.lastname: Zavodny
authors.forename: C C
authors.initials: CC
authors.lastname: Chou
mesh_terms: D000069594:Abatacept; D000595:Amino Acid Sequence; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000378:metabolism; D018122:B7-1 Antigen / Q000378:metabolism; D018106:CD28 Antigens / Q000235:genetics / Q000378:metabolism*; D060908:CTLA-4 Antigen; D016572:Cyclosporine / Q000008:administration & dosage / Q000494:pharmacology; D004357:Drug Synergism; D006801:Humans; D018796:Immunoconjugates; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000096:biosynthesis; D008024:Ligands; D008213:Lymphocyte Activation / Q000187:drug effects; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D018122:B7-1 Antigen; D018106:CD28 Antigens; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D018796:Immunoconjugates; D007166:Immunosuppressive Agents; D007376:Interleukin-2; D008024:Ligands; D011993:Recombinant Fusion Proteins; D000069594:Abatacept; D016572:Cyclosporine